> Isn't it about the response to the request?

High level, yes. Mid/low-level, it really depends on what you're doing. If you're serving static files, sure, use Nginx/Woo. If you're running an evented CL application that deals mostly with network i/o, threading is going to be a tank when you need a hummingbird.

I built cl-async/wookie as parallels for nodejs/express in common lisp.